PAIN ASSESSMENT AND PAIN SCALES Peter Lascarides DO PGY4 PM&R

PAIN ASSESSMENT AND PAIN SCALES Peter Lascarides DO PGY4 PM&R SBUMC / VAMC / SCH

AIM 1. 2. 3. 4.

Provide overview of Pain Assessment Describe various methods of pain assessment Provide familiarity with various pain scales Facilitate the ability to choose appropriate pain scales for different patient groups 5. Assess treatment of pain

Definition of Pain International Association for the Study of Pain • An unpleasant sensory and emotional experience arising from actual or potential tissue damage or described in terms of such damage • Sensory, emotional, cognitive, and behavioral components that are interrelated with environmental, developmental, socio-cultural, and contextual factors

Pain Assessment • By its very definition, pain is an internal, subjective experience that cannot be directly observed by others or measured by the use of physiologic markers or bioassays. • The assessment of pain, therefore, relies largely (and in many cases exclusively) upon the use of self-report.

Pain Assessment • Though the self-report of pain or any other construct is subject to a number of biases, a good deal of effort has been invested in testing and refining self-report methodology within the field of human pain research.

Pain Assessment • The Joint Commission in the United States has set standards for the assessment of pain in hospitalized patients.

Pain Assessment • •

Pain assessment should be ongoing, individualized, and documented. Patients should be asked to describe their pain in terms of the following characteristics: location, radiation, mode of onset, character, temporal pattern, exacerbating and relieving factors, and intensity.

Pain Assessment •

Although pain cannot be considered vital, nor is it a sign, the suggestion that it be routinely measured along with temperature, pulse, blood pressure, and respiratory rate is a powerful reminder to health care providers to attend to their patients' suffering.

Pain Assessment •

Unfortunately, simple routine documentation of pain levels has not been shown in and of itself to lead to any improvement in the quality of pain management. However, proper assessment is still a desirable goal before appropriate treatment.

Assessing Pain • • • • •

Question the patient Use pain rating scales Evaluate behavior & physiologic signs Secure family’s involvement Take action and assess effectiveness

Assessing Pain • The single most reliable indicator of the existence and intensity of pain is the patients self-report of pain. The patients' report of pain should be the primary source of information, since it is more accurate than the observations or others.

Assessing Pain The American Pain Society guidelines for the treatment of acute and cancer pain suggest that each of the following assessment steps occur. • The patient's self-reported pain is charted and displayed. • The intensity of pain and discomfort are assessed and documented at regular intervals (i.e. prior to administration of medication and then after administration of medications) • The degree of pain intensity is measured after allowing sufficient time to pass in order to ensure that a specific pain intervention treatment has occurred.

Question The Patient • Obtain a detailed assessment of pain – HPI, description of pain, experience with pain medications, use of non-pharmacologic techniques, family experience with pain – Quality, location, duration, intensity, radiation, relieving & exacerbating factors, & associated symptoms

• Use appropriate pain scale – Cognitively impaired adults, Sedated patients Children • Pain can be multi-dimensional and therefore, tools can be limited

• Directly ask patients and or family when appropriate

SOCRATES • Site - Where is the pain? • Onset - When did the pain start, was it sudden or gradual? • Character - What is the pain like? • Radiation - Does the pain radiate anywhere? • Associations - Any other signs or symptoms associated with the pain? • Time course - Does the pain follow any pattern? • Exacerbating/Relieving factors - Does anything change the pain? • Severity - How bad is the pain?

Question the Patient • May not be straight forward especially in – Cognitively impaired adults – The learning disabled – Sedated patients in an ICU or operating room setting – Children

Use Pain Rating Scales • Select a scale that is suitable for the patients abilities, age, and preferences • Teach patient to use scale before pain is expected, such as preoperatively • Use same scale with the patient each time pain is assessed

Types of Pain Rating Scales • Single Dimensional Scales – Visual Analog Scale (VAS) – Numerical Rating Scale (NRS) – Verbal Descriptor Scale(s) (VDS)

Types of Pain Rating Scales • Multidimensional Scales – McGill Pain Questionnaire – Short-Form McGill Pain Questionnaire – Brief Pain Inventory – Scales for Neuropathic Pain

Visual Analog Scale

Visual Analog Scale • The VAS is most commonly a straight 100-mm line without demarcations that has the words “no pain” at the left-most end and “worst pain imaginable”(or something similar) at the right-most end. • Benefits of the VAS is that it has been validated and shown to be sensitive to changes in a patient's pain experience. • It is quick to use and relatively easy to understand for most patients. • It avoids the imprecise use of descriptive words to describe pain and allows a meaningful comparison of measurements over time.

Visual Analog Scale • Disadvantages of the VAS is that it attempts to assign a single value to a complex, multidimensional experience. • Some patients have trouble deciding how to represent their pain sensation. They often have no real concept of what “worst pain imaginable” actually means because every experience of pain is different. • It has a false ceiling at the upper-most end. If a patient later time decides that the pain has become worse, the patient has no way to document this change if it was already at maximum.

Verbal Descriptive Scale • The verbal descriptor scale is a list of words, ordered in terms of severity from least to most, that describe the amount of pain that a patient may be experiencing. • Patients are asked to either circle or state the word that best describes their pain intensity at that moment in time. • The benefits of VDS instruments are that they have been validated and are simple for patients to understand and quick to use. • A disadvantage is that a VDS forces patients to select words that are not of their own choosing to describe their pain. – Changes in pain over time are difficult to interpret and probably have different meanings to each individual. – This may especially be a problem with the VDS when only a limited number of possible choices are offered to the patient (i.e. only four to six words).

Verbal Descriptive Scale

Numerical Rating Pain Scale

Numerical Rating Pain Scale • The numerical rating scale offers the individual in pain to rate their pain score. • It is designed to be used by those over the age of 9. • In the numerical scale, the user has the option to verbally rate their scale from 0 to 10 or to place a mark on a line indicating their level of pain. – 0 indicates the absence of pain, while 10 represents the most intense pain possible.

Numerical Rating Pain Scale • The Numerical Rating Pain Scale allows the healthcare provider to rate pain as mild, moderate or severe, which can indicate a potential disability level. • Attempts have been made to define what is considered a meaningful change in the NRS. – At least a 30% reduction or an absolute reduction in the value of at least 2 has been suggested as representing meaningful pain relief to patients

Numerical Rating Pain Scale • Disadvantages of the NRS and VNS are similar to those of the VAS in that they attempt to assign a single number to the pain experience. • They also have the same ceiling effect in that if a value of “10” is chosen and the pain worsens, the patient officially has no way to express this change. • In practice, at least with the VNS, patients often rate their pain as some number higher than 10 (e.g., “15 out of 10”) in an attempt to express their extreme level of pain intensity.

Wong Baker Faces Pain Scale • The Wong Baker Faces Pain Scale combines pictures and numbers to allow pain to be rated by the user. • It can be used in children over the age of 3, and in adults. • The faces range from a smiling face to a sad, crying face. • A numerical rating is assigned to each face, of which there are 6 total.

Wong Baker Faces Pain Scale

0

2

4

6

8

10

McGill Pain Questionnaire (MPQ) • The MPQ and its brief analog, the short-form MPQ, are among the most widely used measures of pain. • In general, the MPQ is considered to be a multidimensional measure of pain quality; however, it also yields numerical indices of several dimensions of the pain experience. • Researchers have proposed three dimensions of the experience of pain: sensory-discriminative, affectivemotivational, and cognitive-evaluative. – The MPQ was created to assess these multiple aspects of pain.

McGill Pain Questionnaire • The McGill Pain Questionnaire consists of groupings of words that describe pain. • The person rating their pain ranks the words in each grouping. Some examples of the words used are tugging, sharp and wretched. • Once the person has rated their pain words, the administrator assigns a numerical score, called the Pain Rating Index.

McGill Pain Questionnaire • • • •

Groups 1-10 = Somatic in nature Groups 11-15 = Affective Group 16 = Evaluative Group 17-20 = Miscellaneous words that are used in the scoring process.

McGill Pain Questionnaire • The benefits of the MPQ are that it is valid, reliable, and consistent in its ability to assign seemingly appropriate descriptions to a given pain experience. • The MPQ may be able to discriminate between different types of pain syndromes. Moreover, it has been shown to be sensitive to changes in the amount of pain experienced by patients in response to receiving various analgesic therapies in both the acute and chronic setting. • One disadvantage of the MPQ is its length. The MPQ should take from 5 to 15 minutes to complete, which for some patients may be seen as more trouble than it is worth. • In addition, this amount of time is prohibitive for use on a repeated basis over a short period (e.g., in a clinical acute pain setting).

Short-Form McGill Pain Questionnaire • The more frequently used short form of the MPQ consists of 15 representative words that form the sensory (11 items) and affective (4 items) categories of the original MPQ. • Each descriptor is ranked on a 0 (“none”) to 3(“severe”) intensity scale. The PPI, along with a VAS, are also included. The short form correlates highly with the original scale, can discriminate among different pain conditions, and may be easier than the original scale for geriatric patients to use.

Short-Form McGill Pain Questionnaire

Special Populations • Common populations that are challenging to assess pain – Children – Cognitively impaired adults – Adults whose cognition is temporarily impaired, by medication or illness – The learning disabled – Sedated patients in an ICU or operating room setting

Nonverbal Pain Indicators • Facial expressions (grimacing) – Less obvious: slight frown, rapid blinking, sad/frightened, any distortion

• Vocalizations (crying, moaning, groaning) – Less obvious: grunting, chanting, calling out, noisy breathing, asking for help

• Body movements (guarding) – Less obvious: rigid, tense posture, fidgeting, pacing, rocking, limping, resistance to moving

Physiological Indications of Acute Pain • • • • • • • •

Dilated pupils Increased perspiration Increased rate/ force of heart rate Increased rate/depth of respirations Increased blood pressure Decreased urine output Decreased peristalsis of GI tract Increased basal metabolic rate

Possible Physiologic Signs of Pain • • • • •

 Pallor or flushing Diaphoresis, palmar sweating  O2 saturation  Vagal tone EEG changes

Possible Physiologic Signs of Pain

Possible Signs of Pain in the Cognitively impaired • • • • • •

Groaning, Crying Changes in sleep/wake cycles Changes in activity level Agitation Rigidity Clenching of fists

Observe for Specific Behaviors that Indicate Local Body Pain • Rolling head from side to side • Lying on side with legs flexed on abdomen • Limping • Refusing to move a body part

Multidimensional Model of Pain Assessment

Dolorimetery • Dolorimetry has been defined as "the measurement of pain sensitivity or pain intensity.“ • A dolorimeter is an instrument used to measure pain threshold and pain tolerance. • Introduced in 1940 by James D. Hardy of Cornell University • There are several kinds of dolorimeters that have been developed. • Dolorimeters apply steady pressure, heat, or electrical stimulation to some area, or move a joint or other body part and determine what level of heat or pressure or electric current or amount of movement produces a sensation of pain.

Dolorimeters

Pediatric Pain • Barriers are often present and include: – Belief that children, especially infants, do not feel pain the way adults do – Lack of routine pain assessment – Lack of knowledge in pain treatment – Belief that preventing pain in children takes too much time and effort

Pediatric Pain • Well documented that children are often undertreated for pain • Specifically in neonates: – Studies show that neonates can experience pain by 26 weeks of gestation • Mature afferent pain transmission

– Untreated pain in neonates lead to increased distress and altered pain response in the future

• Historically children and infants received less postoperative analgesia than adults

Assessment in Children, Neonates & Infants • Challenging • Combines physiologic and behavioral parameters • Many scales available

Possible Signs of Pain in Neonate: Behavioral Variables, cont. Facial expression (most reliable sign): • Eyes tightly closed or opened • Mouth opened, squarish • Furrowing or bulging of brow • Quivering of chin • Deepened nasolabial fold

Facial Expression of Physical Distress

NASOLABIAL FOLD deepened

Children with Cognitive Impairment • Often unable to describe pain • Altered nervous system and experience pain differently • Use behavioral observation scales • Can apply to intubated patients • Must use appropriate observational scales

Question • Which of the following is indicative of pain in a neonate receiving a circumcision? A. B. C. D. E.

A Decrease in insulin Decrease in O2 Saturation Vigorous withdrawal to pain Decrease in transcutaneous PCO2 Bradycardia

Pediatric Pain Scales • Neonates, infants, toddlers (